Pregnancy can be one of the most exciting and positive times of a woman's life, as a new life forms inside her. Unfortunately, for most women, something else entirely is forming on the outside of her body: a lifelong set of stretch marks. Stretch marks have a high chance of occurring any time your weight increases rapidly. And rarely does it ever change as rapidly as it does during pregnancy.
Basics
Though they appear on the surface of your skin, stretch marks originate from deeper within. Beyond the surface, known as the epidermis, lies the dermis, which is the skin's middle layer. Even farther below is the subcutaneous layer. Stretch marks form in the dermis. When the elastic fibers there are stretched beyond their capacity and don't have time to acclimate, such as in quick weight gain, they break. Then you get stretch marks, which start out red and blanch out to a lighter color over time. The exact color depends on your own skin tone.
Prevention
Stretch marks are not entirely avoidable, especially during pregnancy. Many moisturizers and topical vitamins are marketed as preventing stretch marks, but they also share one problem: They're unlikely to penetrate beyond the epidermis. Your best prevention involves what you put into your body, not on it. Drink enough water and other fluids to stay well hydrated. Your dermis needs all the moisture it can get to stay flexible, and topical products rarely reach the dermis. Also, eat a balanced diet and consider a multivitamin, so that the dermis is well supplied with the nutrients it needs to do its jobs. Try not to gain more weight during pregnancy than your doctor recommends.
Topical Treatment
To go by the advertising we see, you'd think stretch marks could be cured through a simple regiment of applying the right lotion or cream every night. It's not quite so simple. Creams used for treatment---many contain retinoids or alpha hydroxy acid---face the same problem as those used for prevention, which is that they rarely reach the dermis. Any improvement you see from using these products is likely to be superficial and fleeting, resulting from effects on the epidermis.
Laser Treatment
Laser treatments come in several forms and are most commonly performed by dermatologists. Some treatments with laser are intended to cause elastin and collagen to grow within the dermis. Such an approach is called pulsed dye laser therapy. It does not damage the skin's surface. Another laser approach is called excimer laser treatment. It causes melanin to be produced. The stretch marks grow darker to more closely match the surrounding skin.
Surgery
Some doctors, particularly plastic surgeons, believe that no treatment for stretch marks is effective except surgery. The tummy tuck is the procedure of choice for women with stretch marks on their bellies caused by pregnancy. The stretch marks are, quite literally, removed. A significant portion of the abdominal skin can be excised during the tummy tuck procedure---the portion, ideally, that includes the worst of your stretch marks. The remaining borders are joined, and you're left with a scar, generally below the bikini line. It's a more expensive treatment, but it's by far the most effective.
